1. Field of the Invention
The present invention relates to a performance control apparatus that sequences data of a music piece for a predetermined duration according to operation by a player, as well as a program for the performance control apparatus.
2. Description of the Related Art
Conventionally, there have been known electronic musical instruments that generate musical tones in response to operation by a player. Such electronic musical instruments are modeled on, for example, pianos and generally carry out performance operations in a manner similar to pianos that are acoustic musical instruments. These electronic musical instruments require skill to perform and much time to learn.
An electronic musical instrument (electronic piano) detects the keying velocity of a player and generates musical tones in accordance with the keying velocity. The electronic piano is equipped with sensors, one for each key, for detecting the keying velocity. The sensors measure the on/off time of multiple contacts, or use elastically deforming members for contacts and utilize the behavior of the members to detect the keying velocity. However, the use of contacts in the sensors causes chattering (repetitive on and off behavior). To prevent the chattering, an apparatus according to Prior Art 1 has been proposed that ignores on/off switching that occurs in a short period of time (see for example Japanese Patent Laid-Open No. 2002-244662).
On the other hand, electronic musical instruments are used by a wide variety of users at all levels from beginners to skilled players. Skilled players want electronic musical instruments capable of providing a wide range of nuance in accordance with performance operations like acoustic musical instruments. In contrast, beginners want electronic musical instruments that allow them to play by simple operations.
In order to meet these demands, an apparatus according to Prior Art 2 has been proposed that automatically plays musical tones for a given time period (for example ½ bar) when a player performs a simple operation (swing by hand) (see, for example, Japanese Patent Laid-Open No. 2000-276141). Japanese Patent Laid-Open No. 2000-276141 describes a musical instrument consisting of multiple slave units and a single master unit. Such an electronic musical instrument generates musical tones in accordance with a player's performance operation. That is, when a player performs a performance operation using a performance operator, information such as the velocity of the performance operation by the player is sent from a slave unit to the master unit, where musical tone data for the musical part assigned to the slave unit is read and a timbre and other characteristics of the musical tone are determined on the basis of the velocity of the player's performance operation.
There has been proposed an apparatus according to Prior Art 3 that sets an upper limit on the velocity of performance operations and, if an operation is performed at a velocity exceeding the predetermined threshold, the operation is assumed to be treated at the upper limit velocity (see, for example, Japanese Patent No. 3720004). The threshold can be varied to change the level of response to performance operations. Thus, the level of difficulty of controlling musical characteristics (stability or musical expression ability) can be adjusted according to player's proficiency level.
As stated above, there has been demand for musical instruments that can be played even by inexperienced players with ease in recent years. It is conceivable that slave units of an electronic musical instrument such as the apparatus according to Prior Art 2 are used as electronic pianos.
However, a beginner can perform wrong operations (accidentally hit neighboring keys at approximately the same time) on an electronic piano that is a slave unit. The apparatus according to Prior Art 1 prevents key chattering but not erroneous performance operations. Furthermore, the keyboard of the apparatus has a complex contact structure and therefore a complex algorithm.
An electronic musical instrument such as the apparatus according to Prior Art 3 treats performance operations performed at a velocity exceeding a predetermined threshold as operations performed at an upper limit velocity to reduce variations in tempo. However, the apparatus does not prevent erroneous performance operations. If keys are depressed at approximately the same time, the tempo of performance significantly changes, causing irregularities in performance.